This project encompasses a wide scope of statistical collaboration and consultation with laboratories and branches within the Division of Intramural Research (DIR), and with other neuroscience units outside NIH. Particular consideration is given to statistical planning and design of experiments, statistical analysis of data, and statistical inference. Examples of current studies include: clinical studies of cholesterol-lowering agents in Neimann-Pick disease, clinical course and outcome of patients with Ceredase(TM) in Gaucher's disease (Developmental and Metabolic Neurology Branch); clinical trials of felbamate for the treatment of intractable complex partial seizures, measurement of the effect of time from last seizure and seizure type on metabolic change as measured by PET; study of epilepsy progression to general tonic~clonic seizures (Epilepsy Research Branch); clinical trial of amantadine for the treatment of post-polio fatigue; optimal sampling procedures to estimate the size of a population of neuronal cells (Clinical Neuroscience Branch); examination of the relationship between MRI change and clinical status in relapsing/remitting MS, clinical trial of the effect of cyclosporine on lesion development in relapsing-remitting MS, modeling lesion recurrence in relapsing-remitting MS, clinical trial of DGS on lesion development in relapsing-remitting MS, monitoring MRI T2 weighted imaging in relapsing-remitting MS (Neuroimmunology Branch); statistical modeling of time-to-motor response complication in L-dopa- treated patients with Parkinson's disease (Experimental Therapeutics Branch); prevalence study of neurologic diseases in the Navajo tribe (Epilepsy Branch); study of abnormal facilitation response to transcranial magnetic stimuation in PD patients; identification of deficits associated with over use syndrome in pianists; three clinical trials of IV-IG in neuromuscular disorders (Medical Neurology Branch); evaluation of neuronal sprouting and behavioral recovery in hemiparkinsonian rats after amnion cell transplantation (Surgical Neurology Branch); validation study of consultations provided by U.S. drug information centers; case-control study of hemorrhagic stroke and alcholism in Santiago, Chile; incidence study of motor neuron disease on Guam (Neuroepidemiology Branch); development of Markov models for rapidy cycling biopolar disorder, examination of the relationship between bright light exposure and hot flashes in menopausal women (NIMH); and study of silent stroke risk factors and their implication for survival of a subsequent stroke.